A radiofrequency identification (RFID) multiplexer, which may be in a network, interprets an RF signal from an RFED reader as RFE) tag interrogation data. A single cable directs an RF signal from the RFID reader and RF control signals and/or RF power through the multiplexer. An RF sampler may be coupled to the cable; and an RF detector detects the RF signal from the cable via the RF sampler. A data decoder decodes and interprets the RF signal as the RFID tag interrogation data and forwards the RFID tag interrogation data to a control logic circuit as a MUX channel-change command. The logic circuit and decoder may be combined in a microcontroller, and an RF backscatter modulator coupled to the cable enables reverse communication with the RFID reader to determine whether another RFID multiplexer is coupled to the RFID multiplexer.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for controlling a multiplexer in an RFID network for communicating with a plurality of RFID tags, comprising transmitting from an RFID reader one or more RFID tag interrogation signals, each consisting of an RF signal having a data format and modulation consistent with an RFID protocol for interrogating an RFID tag so as to obtain an RFID tag response, said RFID tag interrogation signals each including an RFID tag identification number to specify a particular RFID tag which is being interrogated; storing an assigned RFID tag identification number which has been assigned to an RF multiplexer in a first data storage device of the RF multiplexer; storing the assigned RFID tag identification number in a second data storage device of the RFID reader; receiving the one or more RFID tag interrogation signals from the RFID reader at a multiplexer input port of the RF multiplexer, said RF multiplexer capable of selectively routing each said RF signal from said multiplexer input port to one of a plurality of multiplexer output ports through a switching network provided within the RF multiplexer; detecting at the RF multiplexer the occurrence of at least one said RFID tag interrogation signal which comprises a multiplexer channel-change command by monitoring incoming RF signals received at the multiplexer input port, decoding one or more of said RFID tag interrogation signals which are received at the multiplexer input port to obtain RFID data contained in the RFID tag interrogation signal, including the RFID tag identification number, and based on said decoding, selectively identifying that said RFID tag interrogation signal constitutes a multiplexer channel change command; and responsive to said identifying, selectively using the RFID data contained within the RFID tag interrogation signal to control the switching network; wherein the RFID reader uses the assigned RFID tag identification number to address a channel change command to the RF multiplexer, and uses the same signaling format as when communicating an RFID tag interrogation signal to an RFID tag.
2. The method according to claim 1 further comprising using control data comprising a portion of the RFID tag interrogation signal to selectively control an intended channel setting of the RF multiplexer specified by the RFID tag interrogation number.
3. The method according to claim 1 , further comprising transmitting the RFID tag interrogation signals, including those RFID tag interrogation signals comprising said multiplexer channel change command, using an industry standard RFID protocol.
4. The method according to claim 1 , further comprising determining the intended multiplexer channel setting at the RF multiplexer by decoding control data obtained from the RFID tag interrogation signal which has been identified as a multiplexer channel change command.
5. The method according to claim 1 , further comprising obtaining from at least one signal applied to the multiplexer input port a DC voltage, and using the DC voltage as a primary power source for operation of the multiplexer.
6. The method according to claim 1 , further comprising using the DC voltage to power an RF backscatter modulator provided in the multiplexer.
7. The method according to claim 1 , wherein the multiplexer input port comprises a single port, and further comprising using that single port to receive a primary source of input power for powering the operations of the RF multiplexer, to receive control signals which control switching operations of the RF multiplexer, and to supply said RF signals which are to be routed to the plurality of multiplexer output ports.
8. An RFID network for communicating with a plurality of RFID tags, comprising: an RFID reader arranged to transmit one or more RFID tag interrogation signals, each consisting of an RF signal having a data format and modulation consistent with an RFID protocol for interrogating an RFID tag so as to obtain an RFID tag response, said RFID tag interrogation signals each including an RFID tag identification number to specify a particular RFID tag which is being interrogated; a first data storage device in the RF multiplexer in which is stored an assigned RFID tag identification number which has been assigned to an RF multiplexer; a second data storage device in the RFID reader in which is stored the assigned RFID tag identification number; the RF multiplexer coupled to the RFID reader, and receiving the one or more RFID tag interrogation signals from the RFID reader at a multiplexer input port, said RF multiplexer configured to facilitate routing of said RF signals from said multiplexer input port to one of a plurality of multiplexer output ports through a switching network provided within the RF multiplexer; at least one electronic circuit in the RF multiplexer which is arranged to detect the reception of at least on said RFID tag interrogation signal which comprises a multiplexer channel-change command by monitoring incoming RF signals received the multiplexer input port, decoding one or more of said RFID tag interrogation signals which are received at the multiplexer input port to obtain RFID data contained in the RFID tag interrogation signal, including the RFID tag identification number, and based on said decoding, selectively identifying that said RFID tag interrogation signal constitutes a multiplexer channel change command; and switch control circuitry responsive to said identifying of said multiplexer channel change command to selectively control the switching network in accordance with control data contained within the RFID tag interrogation signal; wherein the RFID reader uses the same signaling format for a channel change command as is used when communicating an RFID tag interrogation signal to an RFID tag, and uses the assigned RFID tag identification number to address the channel change command to the RF multiplexer.
9. The RFID network according to claim 8 , wherein control data comprising a portion of the RFID tag interrogation signal specifies an intended channel setting of the RF multiplexer which has been identified by the RFID tag interrogation number.
10. The method according to claim 1 , wherein the multiplexer input port comprises a single port, and wherein that single port receives a primary source of input power for powering the operations of the multiplexer, receives control signals which control switching operations of the multiplexer, and receives said RF signals which are to be routed to the plurality of multiplexer output ports.
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February 15, 2006
January 27, 2015
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